Anesthesiologists spend many hours in relatively straight-forward cases requiring their vigilance, but little direct clinical action. They are often required to perform various paperwork and documentation activities with only an anesthesia system's tabletop as a work surface. Further, there are typically no storage areas for their documents, files, and personal items, such as cell phones, keys, computers, glasses, wallets, purses, etc. Still further, the clinical usage area of a conventional anesthesia system provides no convenient location for syringes, laryngoscopes and other clinical equipment. Conventional designs of anesthesia systems do not accommodate separation of clinical and clerical functions. Most systems provide only modest amounts of space for the anesthesiologist to conduct their work and that must be shared with space used for clinical setup of drugs and instruments.
Further, most current anesthesia system designs provide no articulation of the breathing circuit connections in order to provide a closer pneumatic and sensor link to a patient. Since most current breathing system designs are completely integrated into the anesthesia system, the entire system must be brought in close proximity to the patient in order to have access to the necessary clinical controls while attending to the patient and their airway. Physical constraints in the operating room (OR), due to, but not limited to, surgery type, OR layout, equipment in use, number of personnel required in room, location of personnel, among other variables, add demands to the positioning and structure of the anesthesia system, particularly with regard to the breathing tube port attachments. Breathing tube port attachments often limit the movement of a system, and if twisted or torqued in the wrong direction, there is a risk of disconnect. This physical architecture drives the need for very small footprint systems, which further limit the space available for the anesthesiologist to work on.
While some conventional prior art anesthesia systems allow for the breathing circuit to be articulated away from the system and be placed in close proximity to the patient, these systems still have most of their clinical controls located on the main body of the system, thus making use quite cumbersome.
For example, a typical, conventional anesthesia system employs a breathing circuit on a double-hinged tubular arm that can be moved away from the anesthesia system trolley. This requires draping of the hoses from the breathing system to the trolley, including fresh gas hoses, ventilator drive gas and scavenging gas—all with the possibility of leakage and disconnection. Further, the ventilation, fresh gas flow (FGF), and vaporizer controls on this system are located back on the trolley and away from the user's direct clinical interaction with the patient. This is disadvantageous in that the user constantly needs to turn away from the patient to observe monitoring or make adjustments. Also, the tubular arm is prone to damage by excessive applied forces from beds, people etc. when in the extended position.
Some newer conventional anesthesia systems have fixed the breathing circuit and the controls on the trolley frame, requiring the user to bring the entire system closer to the patient. This has forced a reduction in system size, thereby reducing the “workspace” available to the anesthesiologists. In addition, the anesthesiologist's work area for documentation and storage is also brought proximate to the patient and the clinical field which is undesirable from a clinical and space management standpoint. In the alternative, a user can position the system further away from the patient, but then must constantly turn back and forth from the patient to observe the monitoring and make setting changes.
Hence, currently available anesthesia systems do not provide the necessary storage area, types, or connectivity required by a modern day anesthesiologist. These include power attachments and storage for personal electronic products such as computers, personal digital assistants (PDAs), data/mobile phone devices, personal music devices, wireless headsets etc. Considering that many anesthesiologists do not have offices within the hospitals in which they work, there is a need to satisfy the user of the anesthesia system with enhanced provisions for conducting their daily activities, including case documentation. Some of the features required such as tape dispensers, lined garbage bins and documentation storage areas, etc., are commonly found in office environments, but nevertheless have not been integrated onto currently available anesthesia systems.
What is therefore needed is an anesthesia system which accommodates separation of clinical and clerical functions. What is also needed is an anesthesia system that allows for a portion of the system to be brought closer to the patient such that clinical controls can be accessed while tending to the patient airway, without compromising office space available to the clinician or crowding the patient area. Further, enhanced flexibility is needed on anesthesia systems at the point of attachment of breathing tubes to increase positioning options.
In addition, conventional anesthesia systems are equipped with alarms designed to alert a user to potential technical problems occurring with the system's behavior. These alarms are typically short text strings that fit within a limited space for display on a video screen provided on the anesthesia system and thus cannot provide detailed information describing the technical issue causing the alarm. Also, these alarm strings may be required to be translated into various localized languages that may not reflect the error as unambiguously as the designers may have envisioned in the English language. Some prior art product designs include posting of additional descriptive text or graphic representations on the video screen describing the potential problem being reflected by the alarm. However, these require more focused attention of the clinical user to read or try to correlate the graphic to the actual system that they are using. Oftentimes, the alarms for anesthesia systems occur during a medical emergency situation, creating a confusing and tense situation for the user. In addition, many users are not familiar with the intricate details of the system's function and cannot easily correlate an alarm message to the necessary corrective actions. Further, many users utilize various manufacturer's systems that may use identical or similar alarm messages to define differing equipment failures, problems or behaviors. Also, the shortened text strings and/or translations used for alarm messages do not present sufficient information to allow the user to adequately diagnose the problem. Hence, an improved alarm display system is required.
Some conventional anesthesia machines are currently fitted with “alarm silence” buttons that can be pressed to silence the audible portion of the system's alarms for periods of up to two minutes. This function ensures that the alarm is specifically acknowledged and directly silenced by the user. However, requiring that the alarm silence button be physically pressed can be frustrating to users who have their hands occupied with the care of the patient (e.g. suctioning, re-intubating, administering drugs). Consequently, what is needed is a method for silencing the alarms in a non-contact, yet still reliable manner. This is especially true when the user is being barraged by a series of alarms all related to a single event or clinical condition. For example, alarms that sound during suction of a patient, low pressure alarms, leakage alarms, low minute volume alarms, and low tidal volume alarms may all be activated at different times.
Further, most conventional anesthesia systems have a function referred to as “O2 Flush”. The flush is used principally for refilling the bellows in the presence or upon correction of a leak and for flushing anesthetic agent out of a circle system. Upon activation of the O2 flush for the purposes of refilling the bellows, the bellows fills up with gas that does not contain anesthetic agent. Consequently, the anesthesiologist is required to rebalance the amount of anesthetic agent present in the circuit in order to ensure correct treatment of the patient. Hence, it is desirable to have a single action function in order to provide a high flow similar to that of the O2 flush, while employing levels of mixed gas and anesthetic agent that have been user predefined, in order to enable the bellows to be refilled while preserving the previously set gas mixtures and anesthetic agent levels.
As is commonly known in the art, anesthesia systems with electronic mixing control usually also comprise an emergency bypass valve system that enables a user to set a flow of oxygen in the event of a mixer failure. Some prior art anesthesia systems employ dedicated needle valves to provide the bypass functionality, while others use dedicated mechanical-pneumatic switches to either turn on a bypass valve or revert to an electronic mixer control.
Precise monitoring of the volumes and pressures delivered to ventilated patients is extremely important, especially when presented with pulmonary complications. Measuring these flows and pressures at the patient's airway provides substantial advantages as compared to measuring these parameters inside the anesthesia machine. Current proximal sensors utilize pneumatic or electrical connections back to the anesthesia system. This connection creates significant bulk and weight at the patient's airway that can lead to disconnections and physical pulling on the patient's endotracheal tube. Consequently, many users perceive this to be a significant disadvantage of proximal sensors and choose to perform patient monitoring and delivery control at a less desirable location closer to the anesthesia system. Further, the use of differential pressure type flow sensors and proximal airway pressure sensors require the use of pneumatic tubes to be attached to the anesthesia system. These tubes can be kinked or occluded by wheels of equipment being moved in the OR, causing data loss on the sensor channel. Pneumatic tubes can also be a source of gas leakage from the breathing circuit and their length can result in flow measurement errors due to pneumatic signal transit, common mode errors. Hence, a single, small sensor solution for proximal placement without tubes or connections back to the anesthesia system is therefore needed.
Contemporary anesthetic vaporizer systems contain valves and/or wick systems for transitioning liquid anesthetic agent into a gaseous form. Typically, these systems provide an agent concentration level of 0-10% (although sometimes higher for Suprane) of the gas being used as “fresh gas” or “make up” gas in a circle breathing system. Contemporary devices are rather complex and require precision mechanical components or flow control systems to operate, creating a relatively high cost device. For example, U.S. Pat. No. 6,155,255, assigned to Louis Gibeck AB and herein incorporated by reference in its entirety, proposes a “vaporizer, comprising a vaporizing chamber which includes a gas inlet and a gas outlet and which accommodates a porous liquid delivery device adapted to expose a liquid to the vaporizing chamber for vaporization of said liquid, wherein said porous liquid delivery device is connected to a liquid supplier that communicates with an external liquid source, wherein said porous liquid delivery device is adapted to expose said liquid exclusively through pores in said porous liquid delivery device; and wherein said liquid supplier includes a liquid quantity regulator.” and a “method of vaporizing a liquid, which comprises the steps of: delivering a liquid from an external liquid source to a liquid delivery device; and exposing said liquid in said liquid delivery device to a flowing gas for vaporization of the liquid in contact with the gas, including, conducting said liquid to pores in said liquid delivery device exposing said liquid to the gas exclusively through said pores in said liquid delivery device, and regulating the supply of liquid delivered to said liquid delivery device.”
It is desirable to know the amount of gas flow being moved through the evaporator and have direct means for determining the concentration of anesthetic in the breathable gases that is being produced. It is also desirable to precisely measure the amount of liquid flow into the evaporator for the purposes of computing agent concentrations. Hence, means of incorporating a known vaporizer system into an anesthesia system are required.